1. Field of the Invention
The present invention relates generally to the production of sheet metal cans. It relates further to a sheet metal blank intended for the production of a sheet metal body of a sheet metal can, which sheet metal body is made by a welding of a lateral calender or lap seam, and which sheet metal body is provided with a tear strip extending circumferentially thereof between two substantially parallel pre-scored rupture-or score lines and having a starting end in the shape of a tongue extending beyond the weld seam.
One of the problems of sheet metal cans which are manufactured from sheet metal bodies of the kind mentioned above resides in the placing of a tear strip which can be easily and safely opened by a key in spite of the lateral welding seam.
2. Description of the Prior Art
Presently known designs, in which the tongue which forms the starting end of the tear strip has the same width as the tear strip extending between the two score lines, exhibit time and again the danger that after welding the seam (by a mechanical destruction thereof) the actual rupture lines do not proceed along the score lines, and that rather at least one of the two actual rupture lines proceed away from the pre-scored lines. Such unwanted rupture or tear lines usually proceed angularly inwardly toward the second score line or towards the second unwanted tear line. Quite obviously such leads to a premature destruction of the tear strips and a further opening of the sheet metal can is not possible without the aid of an additional tool.